The technology of the present disclosure relates to an image reading device which performs reading of a manuscript and an image forming device provided with the image reading device.
An image reading device obtains image data by guiding light emitted from a light source and reflected by a manuscript to an image sensor. The image reading device is often installed in an image forming device such as a multi-functional peripheral, a copier or a facsimile device. In order to output image data at a suitable size or to recognize a reading range on a manuscript, some image reading devices perform manuscript size detection. One example of the devices which perform the manuscript size detection will be described below.
One illustrative device includes a manuscript stand on which at least one side of a manuscript is paced according to a manuscript placing standard, a detection position set in a specified position deviated from the manuscript placing standard in order to detect a size of the manuscript, a detecting means for detecting the manuscript in the detection position, a size specifying means for specifying the size of the manuscript placed on the manuscript stand, based on a detection state of the manuscript in the detection position, and a moving means for moving the detecting means to a specified detection position. The size specifying means specifies the size of the manuscript placed on the manuscript stand, based on the detection state of the manuscript in the specified detection position detected by the moving detecting means. Paying attention to the fact that a lens means provided in case of performing image formation by enlarging or reducing an image of a manuscript is configured to move in X and Y directions below the manuscript stand, the image reading device may seek reduce the number of detection sensors and perform accurate detection of a manuscript size.